Biomedical Engineering Reference
In-Depth Information
4.1 Schematic of an ICD system showing two pacing leads, the pulse
generator, and positioning within the thoracic region (courtesy of Medtronic,
Inc.).
pacemaker uses three leads: one placed in the right atrium, one placed in the
right ventricle, and one placed in the left ventricle indirectly. The biventricular
device imparts what
is commonly referred to as cardiac resynchronization
therapy (CRT).
4.2.2
Pacemaker pulse generators
Pacemakers are also called pulse generators or pacemaker cans. While a pulse
generator and leads work together, the generator is implanted separately from
the leads. It has its own implant site and can be removed or replaced with
different units. The earliest pacemakers were simple in their designs, requiring
only a power source and a few transistors to provide a stable series of electrical
output pulses to stimulate the cardiac tissue.
Modern pacemakers provide a wide array of functions including on-board
microprocessors for signal processing and therapy optimization, wireless tele-
metry for communication to the outside world, and diagnostic data storage.
